Aging of Recorded Investment in Loans (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due $ 4,091 $ 4,260
60-89 Days Past Due 435 1,497
Over 90 Days Past Due 776 1,091
Total Past Due 5,302 6,848
Current 287,850 287,630
Recorded investment in loans 293,152 294,478
Residential
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 3,326 3,160
60-89 Days Past Due 305 830
Over 90 Days Past Due 487 701
Total Past Due 4,118 4,691
Current 102,585 102,817
Recorded investment in loans 106,703 107,508
Land
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 159 162
60-89 Days Past Due 0 109
Over 90 Days Past Due 0 12
Total Past Due 159 283
Current 9,961 10,077
Recorded investment in loans 10,120 10,360
Construction
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 0 0
60-89 Days Past Due 0 0
Over 90 Days Past Due 0 0
Total Past Due 0 0
Current 9,683 9,018
Recorded investment in loans 9,683 9,018
Commercial Real Estate
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 109 231
60-89 Days Past Due 0 500
Over 90 Days Past Due 0 49
Total Past Due 109 780
Current 77,789 75,886
Recorded investment in loans 77,898 76,666
Commercial Business
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 0 0
60-89 Days Past Due 0 0
Over 90 Days Past Due 189 189
Total Past Due 189 189
Current 21,055 21,814
Recorded investment in loans 21,244 22,003
Home Equity and Second Mortgage
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 336 411
60-89 Days Past Due 100 24
Over 90 Days Past Due 100 132
Total Past Due 536 567
Current 34,419 34,702
Recorded investment in loans 34,955 35,269
Other Consumer
    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
30-59 Days Past Due 161 296
60-89 Days Past Due 30 34
Over 90 Days Past Due 0 8
Total Past Due 191 338
Current 32,358 33,316
Recorded investment in loans $ 32,549 $ 33,654